Table 1: AAST classification of renal injuries [9].

GradeType of InjuryDescription

INormal contusionMicroscopic or gross hematuria with normal urologic findings
HematomaNonexpanding subcapsular hematomas with no laceration

IIHematomaNonexpanding perinephric (perirenal) hematomas confined to the retroperitoneum
LacerationSuperficial cortical lacerations less than 1 cm in depth without collecting system injury

IIILacerationRenal lacerations greater than 1 cm in depth without collecting system injury

IVLacerationRenal lacerations extending through the renal cortex, medulla, and collecting system
Vascular injury Injuries involving the main renal artery or vein with contained hematoma, segmental infarctions without associated lacerations

VLacerationShattered kidney, ureteropelvic junction avulsions
Vascular injuryComplete laceration (avulsion) or thrombosis of the main renal artery or vein that devascularizes the kidney